Statistics experts, please help! What specific information is provided by an item analysis?

Question

I am struggling to answer the above question in narrative form; completely confused how to answer this in one or two paragraphs. Would greatly appreciate your help! Thank you!

Answer 1

Analysis is about:
* problems rather than solutions
* why rather than how
* discovery rather than invention
* critique rather than acceptance
* decomposition rather than recombination
* insight rather than banality
* clarity rather than confusion
* open rather than closed
* structure rather than disorder
* people rather than machines
* justification rather than assertion
* questions rather than answers
* fact rather than opinion
* freedom rather than dogma
* depth rather than superficiality
* multiple perspectives rather than one
* the future rather than the past
* motion rather than stasis
* outcome rather than process
* ends rather than means
* rigour rather than informality
* relatives rather than absolutes


What Is Data Analysis?
What is the wealth of the United States? Who’s got it? And how
is it changing? What are the consequences of an experimental
drug? Does it work, or does it not, or does its effect depend on conditions? What is the direction of the stock market? Is there a pattern?
What is the historical trend of world climate? Is there evidence of
global warming? — This is a diverse lot of questions with a common element: The answers depend, in part, on data. Human beings ask lots of questions and sometimes, particularly in the sciences, facts help.
Data analysis is a body of methods that help to describe facts, detect patterns, develop explanations, and test hypotheses. It is used in all of the sciences. It is used in business, in administration, and in policy.
The numerical results provided by a data analysis are usually
simple: It finds the number that describes a typical value and it finds differences among numbers. Data analysis finds averages, like the average income or the average temperature, and it finds differences like the difference in income from group to group or the differences in average temperature from year to year. Fundamentally, the numerical answers provided by data analysis are that simple.
But data analysis is not about numbers — it uses them. Data
analysis is about the world, asking, always asking, “How does it
work?” And that’s where data analysis gets tricky.